Filter elements matched with a respective application are used for filtering liquid, gaseous, or pasty media, for example, hydraulic media, process liquids, or even food, like beverages. These filter elements are different with respect to a plurality of parameters, such as the material that is used for the filter material, its pore size, or pressure stability. In many cases these different features cannot be discerned or are not readily detectable by visual inspection.
A fundamental risk exists that a filter element inappropriate or not optimally suited for the respective application will be installed into an existing filter device. As a result of this occurrence the filter device, the medium to be filtered, or the system downstream of the filter device may be damaged. For example, inadequate filtration may result in the abrasive wear or failure of a component in the filter device. Similar problems may also arise when using filter elements that exhibit an inadequate chemical and/or mechanical stability with respect to the media to be filtered. Furthermore, the pollutants released by the inappropriate filter element may contaminate the fluid. In addition, when replacing a used filter element one may forget to insert a new filter element into the related filter housing, the empty filter housing being inadvertently connected to the filter device.
Another problem arises from not being able to determine in a simple way with respect to a filter element that is in use, how long the filter element can still guarantee adequate filtration under the given operating conditions. This problem applies all the more to certain types of filter elements that do not exhibit a continuous reduction in the filtering property; rather their filtering property decreases abruptly after a working period depending on the type of operation.
WO 2004/085027 A1 discloses a system comprising a filter and a related filter element. The filter element is provided with a data memory unit for storing data relating to the filter element.
DE 10 2004 054 172 A1 and WO 2006/050934 A1 disclose a filter element provided with a data memory unit for storing data in its data memory. The data can be read electronically out of the data memory by a read and/or write device disposed outside the filter element. The data items are transmitted by an antenna mounted on the data memory unit and is formed by the data memory unit and transmitting to the data memory unit the energy required to operate the data memory unit. This data memory unit does not have to have its own dedicated source of energy. The distance between the data memory unit and the antenna should be kept as low as possible to guarantee a reliable transmission of both energy and data.